Papermaking machine



April 30, 1968 E. P. LAUMER PAPEHMAKING MACHINE Filed April 19, 1966 VII/I United States Patent 3,389,734 PAPERMAKING MACHINE Edward P. Laumer, Neenah, Wis., assignor to Kimberly- Clark Corporation, Neenah, Wis., a corporation of Delaware Filed Apr. 19, 1966, Ser. No. 543,647 4 Claims. (Cl. 271-76) ABSTRACT OF THE DISCLOSURE An air table positioned between discharge ends of high speed sheet carrying tapes and the sheet receiving ends of low speed sheet carrying tapes and having air discharge openings therethrough for discharging air upwardly through the table. The table is positioned adjacent to and approximately at the same level as the upper sheet carrying stretches of the low speed tapes and is positioned adjacent to the upper quadrant of a roll supporting the high speed tapes so that air discharged through the openings and traveling along the table surface holds a preceding sheet down due to the Bernoulli etfect, and so that air from these openings travels along the upper quadrant of the high speed roll for blowing the leading edge of a succeeding sheet upwardly to cause it to clear the trailing edge of the preceding sheet.

The present invention relates generally to machines for acting on sheet material and is particularly directed to apparatus for feeding paper sheets, as from a cutter to a layboy, for example.

In the production of stacks of paper sheets from rolls of paper, the webs of paper may be cut by a rotary cutter into sheets of predetermined length; and these sheets may then be fed through a system of conveyor tapes to a lay-boy for forming a stack of cut sheets. For high speed operation of the cutter, preferably the sheets are slowed down by the conveyor system so that the edges of the sheets are not damaged as they strike a backstop in the layboy; and, assuming that the sheets are initially spaced as they leave the cutter, overlapping of the sheets is produced as they are slowed down in this manner.

It is an object of the present invention to provide improved mechanism for vertically separating the sheets as they are brought into overlapping relationship so that there is no interference and abutting of the sheets together at this time and so that uniform sheet overlapping results.

In a preferred form of the invention, a table is provided between high speed sheet conveying tapes and low speed sheet conveying tapes. The high speed tapes are disposed at a higher level than the low speed tapes, and the table is disposed at substantially the same level as the low speed tapes. The table is provided with a plurality of openings in it, and a source of air under pressure is connected to these openings so that air jets upwardly through them. The flow of air through these openings has two eflects, namely, of sucking down the trailing edge of a prior sheet after the sheet has been buckled downwardly into contact with the table as the sheet transfers from the high speed tapes to the low speed tapes, this sucking action being due to the Bernoulli efiect; and secondly, of causing the leading end of the succeeding sheet to stay in a raised position by blowing it upwardly so that it clears the trailing end of the preceding sheet.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects, and such other objects, as will be apparent from the following description of a preferred form of the invention, illustrated with reference to the accompanying drawings, wherein:

3,380,734 Patented Apr. 30, 1968 FIG. 1 is a diagrammatic side elevational view of a tape system including high speed tapes and low speed tapes;

FIG. 2 is a cross-sectional view of a table having air jets in its upper surface and disposed between the high speed tapes and the low speed tapes; and,

FIG. 3 is a partial perspective view of the table.

Like characters of reference designate like parts in the several views.

Referring now to the drawings and to FIG. 1 in particular, the illustrated sheet conveying system may be seen to comprise a series of high speed tapes 10, a series of additional high speed tapes 11 and a series of low speed tapes 12. The high speed tapes 10 are supported by a pair of spaced rolls 13 and 14, and the low speed tapes 12 are supported by a pair of spaced rolls 15 and 16. It will be noted that there is a substantial spacing between the rolls 14 and 15, and the roll 14 is disposed at a level higher than the roll 15. Likewise, the upper stretches of the tapes 1% are at a higher level than the upper stretches of the tapes 12, and all stretches of the tapes are approximately horizontal. An air table 17 is disposed between the rolls 14 and 15 and thereby between the high and loW speed tapes 1! and 12 as illustrated.

The high speed tapes 11 are movably disposed about rolls 18, 19, 20, 21 and 22, and it Will be noted that the rolls 19 and 21 are so disposed that the upper stretches of the high speed tapes 10 are nearly at the same level and co-incident with the adjacent lower stretches of the high speed tapes 11. The roll 19 bears on the low speed tapes 12 and preferably has spaced grooves in its periphery for the high speed tapes 11 so that the tapes 11 are slightly out of contact with the tapes 12 in the vicinity of the roll 19. For each set of tapes 10, 11 and 12, one of the respective sets of supporting rolls is driven so as to move the tapes at their respective speeds, with the tapes 10 and 11 moving substantially at the same high speed and the tapes 12 moving at a relatively low speed.

The air table 17 comprises a closed supporting casing 23 having an air supply conduit 24 connected to it. The table 17 is suitably supported with respect to the rolls 14 and 15 so that its upper surface is substantially horizontal and at the same level as the upper stretches of the tapes 12 in the vicinity of the roll 15, and the upper surface of the table 17 extends in the same general direction as do these upper stretches of the tapes 12, namely, horizontally. The table 17 is provided with a plurality of spaced openings 25 extending upwardly through it normally to its upper surface, and a pointed valve stem 26 is positioned immediately below each of the openings 25 for the purpose of efiectively opening or closing the opening. Each of the valve stems 26 is mounted on an adjustment screw 27 threadly extending through the lower portion of the casing 23 for adjusting the vertical position of the valve stem 26.

An air ionizer or ozone emitter 28 is disposed in the casing 23 and is suitably fixed with respect to the table 17. The unit 28 is of conventional construction and, therefore, is not further described.

The illustrated tape system is intended particularly to be used in connection with a cutter for supplying sheets to the tape system and a layboy for receiving sheets from the tape system. Such a cutter and layboy and, in fact, a tape conveyor system of the same general type as the herein described and illustrated tape system are, for example, disclosed in the co-pending application of Delton C. Beaulieu and Huron C. Brien, Serial No. 351,170, filed March 11, 1964 (now Pat. No. 3,253,265, issued June 28, 1966).

In the operation of the herein illustrated and described tape system, spaced cut sheets, such as sheets a and b (see FIG. 2), pass between and are conveyed by the coextensive stretches of the high speed tapes and 11 which move at substantially the same speed. The sheet (1 passes downwardly from the roll 14 onto the upper stretches of the tapes 12, and the leading end of the sheet a is blown upwardly by the jets of air passing through the upwardly directed openings 25. As the sheet a passes onto the low speed tapes 12, its forward movement is thus arrested so that the sheet buckles downwardly to make contact with the upper surface of the table 17. Upward buckling of the sheet a is prevented by the stretches of tapes 11 overlying the table 17. The air jetting through the openings now has the effect of sucking the sheet a downwardly and holding it in quite tight contact with the upper surface of the table 17 as the sheet continues to move, the air at this time passing transversely outwardly from the openings 25 and along and over the upper surface of the table 17 and beneath the sheet a.

As the trailing end of the sheet a reaches and passes downwardly over the roll 14, the sheet b reaches the roll and starts to move downwardly over the surface of the roll 14. At this time, the air that is flowing rearwardly along the surface of the table 17 and under the sheet a from the openings 25 toward the roll 14 travels upwardly along the surface of the roll 14 and blows the leading end of the sheet b upwardly. The upward How of air in this manner along the surface of the roll 14 causes the leading end of the sheet [1, as the sheet b continues its movement in the forward direction at the high speed of the tapes 10, to stay in a raised position for a short time so that it clears and overlies the trailing end of the preceding sheet a which is drawn downwardly on the surface of the roll 14 and travels tightly across the surface of the table 17. Thus, an overlap has been established between the sheet b and the sheet a, and each succeeding sheet has a similar overlap established between it and the preceding sheet.

Although the diameters of the openings 25 and the pressure of the air within the casing 23 may be varied, I have found that opening diameters from -inch to A3- inch are very satisfactory and that, preferably, an air pressure of pounds per square inch minimum should be used in the casing 23, with air pressures of to pounds per square inch being entirely satisfactory. The air blowing through the upwardly directed openings 25 in the air table 17, with the table being placed at substantially the same level as the sheet receiving ends of the low speed tapes 12 and substantially below the level of the discharge ends of the high speed tapes 10, advantageously sucks the trailing end of a preceding sheet downwardly onto the surface of the table 17 due to the Bernoulli effect, while at the same time blowing the leading end of a succeeding sheet upwardly, so as to assure an overlap between the succeeding sheet and the preceding sheet.

I wish it to be understood that the invention is not to be limited to the specific constructions, arrangements and devices shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

1. In a handling system for sheets of sheet material, the combination of a series of high speed sheet carrying tapes and a series of low speed sheet carrying tapes, a plurality of rolls for movably supporting said high speed tapes in the form of a loop so that sheets may be carried on the upper stretches of the tapes and a plurality of rol for movably supporting said low speed tapes in the form of a loop so that sheets may be carried on the upper stretches of the low speed tapes and may transfer from said high speed tapes to said low speed tapes, said high speed tape rolls including a high speed roll at the sheet discharge ends of the high speed tapes and said low speed tape rolls including a low speed roll at the sheet receiving ends of the low speed tapes which has its uppermost peripheral surface at a lower level than such surface of said high speed roll, an air table disposed between said high speed roll and said low speed roll and having a generally horizontal upper table surface with a plurality of generally vertically extending air discharge openings therethrough, and a source of air pressure connected to the lower ends of said openings so that air passes upwardly through the openings, one edge of said air table being located adjacent to the periphery of said low speed roll approximately at the level of said upper stretches of said low speed tapes as they pass around said low speed roll and the opposite edge of said air table being located adjacent to the upper quadrant of the periphery of said high speed roll that faces said low speed roll and below the level of said upper stretches of said high speed tapes so that air passing upwardly through said openings and along the upper surface of the table functions to hold the trailing end of a preceding sheet passing from said high speed tapes to said low speed tapes onto the upper table surface and air traveling from said openings travels upwardly along said upper quadrant of the periphery of said high speed roll so as to blow the leading end of a succeeding sheet passing from said high speed tapes to said low speed tapes into a raised position whereby the succeeding sheet clears the trailing end of the preceding sheet.

2. In a sheet handling system, the combination as set forth in claim 1, said upper stretches of said high speed tapes and of said low speed tapes being substantially horizontal and the upper surface of said table being substantially horizontal.

3. In a sheet handlin system, the combination as set forth in claim 1, said openings having diameters of inch to Aa-inch and the air supplied to said openings being at a pressure of 35 pounds per square inch to 50 pounds per square inch and said openings extending through said air table substantially normal to the upper surface of the table.

4. In a sheet handling system, the combination as set forth in claim 1, and a second series of high speed tapes and a plurality of rolls for movably supporting the second series of high speed tapes in the form of a loop with the lower stretches of these tapes being located above said first mentioned series of high speed tapes and above said table for preventing upward buckling of a sheet as it travels from said first mentioned high speed tapes onto said low speed tapes.

References Cited UNITED STATES PATENTS 2,261,971 11/1941 Matthews 271-76 3,315,956 4/ 1967 Lyman 271-76 3,319,856 5/1967 Stanley 27174 RICHARD E. AEGERTER, Primary Examiner. 

